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Does a Blood Sample Search Warrant Cover Testing for Evidence of Intoxication?

Updated: Jul 9, 2023 @ 2:23 pm

Reading Time: 3 Minutes

When police suspect that drunk driving played a role in a car accident, officers may seek a search warrant in order to take a sample of the driver’s blood. But does such a warrant automatically cover the right to analyze the blood sample as well?

A recent decision from a Houston appeals court, Davis v. State, addressed this exact question.

Houston Court Rejects Arguments that Warrant Was Limited in Scope, Executed Too Late

Auto Accident Leads to DWI Charge

This case began with a December 2017 auto accident. The defendant rear-ended the vehicle in front of her, pushing that car into a third vehicle. The third driver said she noticed the defendant’s “body language was off” and that she was slurring her words. This prompted the driver to call the police to the accident scene.

Deputy Observes Signs of Intoxication, Arrests Motorist

A Harris County sheriff’s deputy arrived and also said he observed the defendant exhibiting “slurred speech, poor balance, red glassy eyes, and an odor of alcohol.”

At this point, the defendant voluntarily admitted to “drinking two beers.” The deputy said he also could see several open and empty beer cans in the defendant’s car. After administering field sobriety tests, the deputy placed the defendant under arrest for DWI.

Blood Test Administered

The deputy subsequently applied for and received, a search warrant from a local magistrate. The warrant authorized the search and seizure of “blood samples” from the defendant.

The samples were obtained and tested by a forensic laboratory, which concluded the defendant’s blood-alcohol concentration was 01.22 percent, which was nearly three times the legal limit for DWI in Texas.

Defendant Challenges Admissibility of Blood Test Results

Before a trial court, the defendant argued the results of the blood test should not be admitted as evidence. The defendant did not challenge the legality of the search warrant itself. Rather, she argued the warrant only covered the “seizure of the blood sample, but not analysis of the blood.” Furthermore, even if the warrant did permit analysis, it did not take place until after the warrant expired.

Appeals Court Uphold Lower Court’s Decision

The trial judge rejected both arguments, as did the Texas First District Court of Appeals. Affirming the defendant’s ultimate conviction on misdemeanor DWI charges, the First District explained that “both the collection and the testing of the blood samples were within the scope of the warrant.” The warrant was issued to collect evidence of a possible crime, i.e., drunk driving. In this context, the evidence was not the blood sample; it was the results of the laboratory analysis of the blood sample.

As for the other issue raised by the defendant, the appeals court noted that under Texas law a search warrant must normally be “executed” within three days of being issued. But “execution” refers to when the blood samples were taken, not when they were tested. Since the sample was taken the same day the warrant was issued–i.e., the date of the defendant’s arrest–there was no violation of the defendant’s rights.

Need Legal Advice for a Texas DWI Case?

Call Atty. Tad Nelson Today!

Even when these types of constitutional challenges do not succeed, they still provide an important form of accountability for police and prosecutors. Any defects in the process of obtaining or executing a search warrant can invalidate critical evidence in a DWI case. And if you are the one facing criminal charges, that can mean the difference between an acquittal and possible jail time.

If you need legal advice or representation from a qualified Houston criminal defense attorney following a purported DWI accident, contact the Law Offices of Tad Nelson & Associates in Houston, Galveston or League City today.

Houston DWI Lawyer Tad A Nelson is Board Certified in Criminal Law by the TBLS.

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